1. Field of Invention
This invention relates generally to electronic document reading systems. In particular, this invention is directed to an electronic document reading system that suggests other related documents when displaying a first document.
2. Description of Related Art
Retrieving documents similar to a document identified by the user as being related is known as relevance feedback. Relevance feedback is described in xe2x80x9cIntroduction to Modem Information Retrievalxe2x80x9d, G. Salton et al., McGraw Hill, (1983), incorporated herein by reference in its entirety. Interfaces that support relevance feedback conventionally require explicit action on the part of the reader and do not spontaneously offer suggestions of relevant documents. Information exploration interfaces designed for window-based computing environments typically present search results for other relevant documents via lists in a separate window or by replacing the visible document with the search results. These systems are very intrusive and interrupt the reading process.
Hypertext interfaces display links to documents relevant to a source document either by providing a margin that contains the links or by embedding the links in the text of the source document in the manner pioneered by xe2x80x9cHyperties.xe2x80x9d This system is described in xe2x80x9cUser Interface Design for the Hyperties Electronic Encyclopediaxe2x80x9d, by Shneiderman, Proceedings of Hypertext ""87, November 1987, Chapel Hill, N.C. incorporated herein by reference in its entirety. However, these links are static and are created along with the source document by the hypertext author. Some systems, such as Trellis, display links dynamically, but only from a fixed set of previously-defined links. Trellis is described in xe2x80x9cProgrammable Browsing Semantics and Trellisxe2x80x9d, by R. Furuta et al. Proceedings of Hypertext ""89, November 1989, Pittsburgh, Pa., ACM Press, incorporated herein by reference n its entirety.
The HieNet System uses inter-node similarity measures to create hypertext links based on links previously created by the hypertext author. This system is described in xe2x80x9cHienet: A User-Centered Approach for Automatic Link Generationxe2x80x9d, D. T. Chang, Proceedings of Hypertext ""93, November 1993, Seattle, Wash., ACM Press, incorporated herein by reference in its entirety. When the author creates a link from a document A to a document B, the system automatically adds links from all documents similar to document A to all documents similar to document B. Anchors for these automatically-generated links are represented by icons in the margin of the various documents. Clicking on an icon displays a pop-up menu that contains a list of possible destination documents that are ranked by relevance to the query. Again, this system relies on links previously created by the author.
Other conventional systems relate to hypertext-like ways of displaying search results. HieNet displays automatic links in the margin, but anchors in the margin are not relevant to the content of the passage adjacent to the anchor. HieNet does not distinguish between document-document and passage-document links. Furthermore, HieNet does not indicate the number and nature of the documents reachable through the margin links.
Visualization of Information Retrieval System (hereinafter VOIR) is described in xe2x80x9cQueries? Links? Is There a Difference?xe2x80x9d, Proceedings of CHI ""97, G. Golovinsky, March 1997, Atlanta, Ga., ACM Press and in xe2x80x9cWhat the Query Told the Link: The Integration of Hypertext and Information Retrievalxe2x80x9d, Proceedings of Hypertext ""97, G. Golovinsky, April 1997, Southhampton, UK, ACM Press, each incorporated herein by reference in its entirety. VOIR is a mechanism that dynamically creates and resolves hypertext links with queries that are computed from the text surrounding a selected anchor. VOIR uses queries to retrieve sets of documents that are related to the passage containing the selected anchor. VOIR does not show the user links that have pre-established relationships. Rather, to submit a query and to establish a relationship, the user has to pause and select an anchor. VOIR was designed specifically to support interactive information exploration, rather than to facilitate the reading process. Thus, VOIR""s focus is supporting navigation between documents. The user is thus expected to devote much cognitive effort to browsing. Furthermore, VOIR does not permit the user to annotate or tag documents. VOIR also does not indicate which link was selected to generate a particular display.
A background information retrieval process called the Remembrance Agent (hereinafter RA) is described in xe2x80x9cA Continuously Running Automated Information Retrieval Systemxe2x80x9d, B. J. Rhodes et al. Proceedings of The First International Conference on the Practical Application of Intelligent Agents in Multi-Agent Technology, PAAM ""96, April, 1997reference in its entirety. RA operates in an EMACS text window and suggests documents related to the last few lines of text typed by the user. RA is designed to search through a user""s private data to suggest documents related to the text being typed. However, these suggestions are ephemeral and relate only to text that is currently being written. RA does not support reading tasks because it continuously replaces suggestions as the user edits the document.
QRL is a query-based information exploration interface that uses ink-like marks on text to specify boolean queries. This system is described in xe2x80x9cQueries-R-Links: Graphical Markup for Text Navigationxe2x80x9d, by G. Golovchinsky et al., Proceedings of INTERCHI ""93, April 1993, Amsterdam, The Netherlands, ACM Press, incorporated herein by reference in its entirety. Query terms are selected with rectangles. Lines connect the rectangles to represent boolean AND operators.
All of these systems require extensive user interaction to generate links to related documents or only support writing. An electronic document reading system is needed that passively and unobtrusively generates links to related documents to support reading.
This invention provides a method and a system for passively showing the reader related documents without interfering with the reading process.
The invention further provides intuitive support for reading by automatically detecting portions of other documents or other portions of the same document that are potentially of interest to the reader based on the reader""s interaction with the portion of the source document being read. When people read text, they often make annotations to highlight interesting or controversial passages and terms. The presence or relative density of such marks and scribbles may be used as an indicator of the relative interest that the reader has in a particular passage. When a large body of documents related to the document being read is available, the reader may be interested in finding related portions of other documents or other portions of the same document as part of the reading process.
References to portions of other documents or to other portions of the same document that are related to specific passages of interest to the user are placed in the source document""s margins and references to other documents that are similar overall to the source document are inserted as end notes. The system and method of this invention maintain the links once they have been identified to facilitate non-linear reading and skimming.
The system and method of this invention infer a user""s interests from annotations that are made to a source document by the user while the user is reading the source document. Therefore, the system and method of this invention minimize cognitive overhead in at least two ways: 1) no explicit query is required to identify portions of other documents and other portions of the same document that are related to the portion of the source document that has been annotated by the user; and 2) selectable links to the portions of other related documents or other portions of the same document are provided unobtrusively in the margins and at the end of the source document. An example of this is shown in FIGS. 2 and 3, respectively.
The system and method of this invention also introduce suggestions to the reader in a manner that is compatible with other interactions, rather than burdening the user with modal dialogues. Portions of other documents or other portions of the same document that are suggested by the method and system of this invention are accessible by following selectable links. However, the system and method of this invention does not force the user to act on a suggestion when it is made. Rather, the user can act on the suggestion when (or if) it makes sense to the user to do so. The system and method of this invention represent the type of the suggested or referenced portion with an icon and provide a textual label to the icon to give users a better understanding of the target of the link.
These and other features and advantages of this invention are described in or are apparent from the following detailed description of the preferred embodiments.